What is Central Pontine Myelinolysis?
Central pontine Myelinolysis (CPM) is a rare neurological disorder affecting the brain. Central pontine Myelinolysis is characterized by demyelination that is found affecting the central portion of the base of the pons. It is a part of the osmotic demyelination syndrome (ODS). The other type is called extrapontine myelinolysis (EPM), which occurs when the myelin is destroyed, in the areas of the brain that are not in the brain stem.
According to the central institute of neurological disorder and stroke, around 10 percent of people suffering from CPM also have EPM.(1) The mortality rate is 50 percent, but an early diagnosis can really help.
Central pontine Myelinolysis is known to be more common in adults than in children.
Pontine refers to pons that is a part of the brain stem. Myelinolysis means the myelin sheath covering the nerve cells including pontine nerve cells is destroyed.
The destruction of the myelin sheath is not spontaneous and usually happens due to another illness or medical condition.
The cure of the Central pontine Myelinolysis is not yet known but its symptoms can be treated.
Causes and Risk Factors of Central Pontine Myelinolysis
A rapid increase in blood sodium levels is the most common cause of Central pontine Myelinolysis.
Sodium regulates electrolyte minerals that help regulate fluid levels. This ensures the cells are well-hydrated.
Central pontine Myelinolysis occurs when the blood sodium levels increase rapidly. The reason is not clear but a rapid shift of water in the brain cells is believed to be involved.
Those treated for low blood sodium levels (hyponatremia) are more at risk of developing Central pontine Myelinolysis. Other symptoms caused by hyponatremia are:
Low sodium levels are treated with infusion of sodium solution, which can help the sodium levels to rise quickly if administered properly.
A person is more likely to develop Central pontine Myelinolysis if the hyponatremia goes untreated.
A few other diseases such as chronic alcohol misuse, liver disease, and malnutrition can increase the risk of Central pontine Myelinolysis. These conditions can bring about a change in sodium levels.
Symptoms of Central Pontine Myelinolysis
The symptom presentation of a person suffering from Central pontine Myelinolysis involves both Physical as well as cognitive symptoms.
There is damage to the myelin sheath that can cause damage to the brain stem nerves. This damage interferes with the communication between the nervous system and the muscles. There may be:
- Muscle weakness of the face, arms, and legs
- Delayed or poor reflexes
- Tremors
- Difficulty in swallowing
- Poor balance
- Slow speech and poor enunciation
Central pontine Myelinolysis can also lead to damage to the brain cells that can affect mental as well as physical health.
There may be confusion, hallucination as well as a delirious state. Some may even experience intellectual impairment due to Central pontine Myelinolysis.
How to Diagnose Central Pontine Myelinolysis?
Blood tests are done to measure the blood sodium levels for diagnosis of Central pontine Myelinolysis.
An MRI can diagnose the damage to the brain stem.
MRI of the head can help detect the damage to the brain stem.
A brainstem auditory evoked response test (BAER) is also advised to measure the response time and brain activity heard with each sound.
Treatment for Central Pontine Myelinolysis
Central pontine Myelinolysis is an emergency situation and should be treated on an emergency basis. Medical care should be reached if the symptoms are consistent.
Treatment for Central pontine Myelinolysis focuses mainly on managing symptoms and it includes:
- Fluids and medications to regulate sodium levels
- Physical therapy that helps improve balance and retain range of motion
- Dopaminergic medications for people who develop Parkinson’s-like symptoms. These may increase dopamine, manage tremors, and also manage difficulties with speech or swallowing.
How to Prevent Central Pontine Myelinolysis?
Keeping the blood sodium levels under control can help prevent Central pontine Myelinolysis.
Those with a medical condition that puts a person at risk of hyponatremia should make sure about the signs of low blood sodium and should keep up with the treatment.
Staying hydrated can also help maintain the body’s fluid balance and proper sodium levels.
People with Central pontine Myelinolysis should seek appropriate treatment. The nerve damage can get chronic and lead to permanent disabilities. Rare, but Central pontine Myelinolysis can also lead to locked-in syndrome (in which a person loses all mobility and muscle control), coma, and even death.
The survival rate of people with central pontine Myelinolysis is around 94%.(2)
